Neil Conway <[EMAIL PROTECTED]> writes: > Interesting -- I wonder if it would be possible for the optimizer to > detect this and avoid the redundant inner sort ... (/me muses to > himself)
I think the ability to generate two sort steps is a feature, not a bug. This has been often requested in connection with user-defined aggregates, where it's handy to be able to control the order of arrival of rows at the aggregation function. If the optimizer suppressed the inner sort then we'd lose that ability. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match